What is the best upgrade path from HDP 2.1 to HDP 2.3.2 ?
We already had some clusters going from HDP 2.1 directly to HDP 2.3.2 and apparently only minor issues along the way, nothing serious though.
Ambari 2.1.3 will support Express Upgrade from HDP 2.1 -> 2.3 directly. That feature is similar to Rolling Upgrade, except that the cluster takes downtime. ETA is December.